'''hdmi_safe''' Use "safe mode" settings to try to boot with maximum hdmi compatibility.

+

'''hdmi_safe''' Use "safe mode" settings to try to boot with maximum hdmi compatibility. This is the same as the combination of: hdmi_force_hotplug=1, config_hdmi_boost=4, hdmi_group=1, hdmi_mode=1, disable_overscan=0

'''hdmi_ignore_edid''' Enables the ignoring of EDID/display data if your display is a crappy Chinese one

'''hdmi_ignore_edid''' Enables the ignoring of EDID/display data if your display is a crappy Chinese one

hdmi_ignore_edid=0xa5000080

hdmi_ignore_edid=0xa5000080

+

+

'''hdmi_edid_file''' when set to 1, will read the edid data from the edid.dat file instead of from the monitor.<ref name=hdmi_edid_file>http://www.raspberrypi.org/phpBB3/viewtopic.php?p=173430#p173430</ref>

+

hdmi_edid_file=1

'''hdmi_force_edid_audio''' Pretends all audio formats are supported by display, allowing passthrough of DTS/AC3 even when not reported as supported.

'''hdmi_force_edid_audio''' Pretends all audio formats are supported by display, allowing passthrough of DTS/AC3 even when not reported as supported.

hdmi_force_edid_audio=1

hdmi_force_edid_audio=1

−

'''edid_format_smart_match''' Allow fuzzy matching of modes described in edid. Picks the standard mode with matching resolution and closest framerate even if blanking is wrong.

+

'''avoid_edid_fuzzy_match''' Avoid fuzzy matching of modes described in edid. Picks the standard mode with matching resolution and closest framerate even if blanking is wrong.

'''avoid_safe_mode''' if set to 1, [[RPI_safe_mode|safe_mode]] boot won't be enabled. Default 0

−

'''boot_delay''' Waits for given number of seconds in start.elf before loading kernel.img.

+

=Overclocking=

+

'''WARNING:''' Setting any of the parameters which overvolt your Raspberry Pi can set a permanent bit within the SOC and your warranty is void. Warranty will be voided when you use force_turbo or current_limit_override or temp_limit>85 together with over_voltage>0.<ref name=over_voltage>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&sid=eda2ef9b994cdfb28eef3e8a20d1a1e8&start=350#p176865</ref> So If you care about the warranty, do not adjust voltage.

−

'''avoid_safe_mode''' If set to one, [[RPI_safe_mode|safe_mode]] boot won't be enabled.

+

The latest kernel has a [http://www.pantz.org/software/cpufreq/usingcpufreqonlinux.html cpufreq] kernel driver with the "ondemand" governor enabled by default. It has no effect if you have no overclock settings.

+

But when you do, the arm frequency will vary with processor load. Non default values are only used when needed according to the used governor. You can adjust the minimum values with the *_min config options or disable dynamic clocking with force_turbo=1. <ref name=cpufreq>http://www.raspberrypi.org/phpBB3/viewtopic.php?p=169726#p169726</ref>

−

=Overclocking configuration=

+

Overclock and overvoltage will be disabled at runtime when the SoC reaches 85°C to cool it down . You should not hit the limit, even with maximum settings at 25°C ambient temperature. <ref name=freq_overheat>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=11579#p169872</ref>

−

'''WARNING:''' Setting any of the parameters which over volt your Raspberry Pi will set a permanent bit within the SOC and your warranty is void. So If you care about the warranty do not adjust voltage.

+

Also at your own risk you can try [[RPi_config_for_your_TV|overscan settings]] from our wiki. These were [http://www.raspberrypi.org/forum/features-and-requests/should-we-make-a-wiki-page-for-overscan-settings posted] on the forum and are not confimed to work.

Also at your own risk you can try [[RPi_config_for_your_TV|overscan settings]] from our wiki. These were [http://www.raspberrypi.org/forum/features-and-requests/should-we-make-a-wiki-page-for-overscan-settings posted] on the forum and are not confimed to work.

Line 319:

Line 370:

|-

|-

!align="right"|arm_freq

!align="right"|arm_freq

−

| frequency of ARM in MHz. Default 700.

+

| Frequency of ARM in MHz. Default 700

|-

|-

!align="right"|gpu_freq

!align="right"|gpu_freq

−

| Sets core_freq, h264_freq, isp_freq, v3d_freq together.

+

| Sets core_freq, h264_freq, isp_freq, v3d_freq together. Default 250

|-

|-

!align="right"|core_freq

!align="right"|core_freq

−

| frequency of GPU processor core in MHz. It have an impact on ARM performance since it drives L2 cache. Default 250.

+

| Frequency of GPU processor core in MHz. It have an impact on ARM performance since it drives L2 cache. Default 250

|-

|-

!align="right"|h264_freq

!align="right"|h264_freq

−

| frequency of hardware video block in MHz. Default 250.

+

| Frequency of hardware video block in MHz. Default 250

|-

|-

!align="right"|isp_freq

!align="right"|isp_freq

−

| frequency of image sensor pipeline block in MHz. Default 250.

+

| Frequency of image sensor pipeline block in MHz. Default 250

|-

|-

!align="right"|v3d_freq

!align="right"|v3d_freq

−

| frequency of 3D block in MHz. Default 250.

+

| Frequency of 3D block in MHz. Default 250

|-

|-

!align="right"|avoid_pwm_pll

!align="right"|avoid_pwm_pll

Line 340:

Line 391:

|-

|-

!align="right"|sdram_freq

!align="right"|sdram_freq

−

| frequency of SDRAM in MHz. Default 400.

+

| Frequency of SDRAM in MHz. Default 400

|-

|-

!align="right"|over_voltage

!align="right"|over_voltage

−

| ARM/GPU core voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V) <ref name=voltages>What this means is that you can specify -16 and expect about 0.8V as the GPU/core voltage. This is 0.4V below the normal value of 1.2. If you specify 16, you'd get 0.4V ABOVE the normal value of 1.2V, or 1.6V. The fact that someone carefully specified "8" and "1.4V" as the upper limit in the examples leads me to think that it is likely to shorten the life of your raspberry pi significantly if you would specify values above "8". So: don't specify values above zero, but if you do, don't go above 8.</ref>

+

| ARM/GPU core voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. force_turbo will allow values higher than 6. Default 0 (1.2V) <ref name=voltages>What this means is that you can specify -16 and expect about 0.8V as the GPU/core voltage. This is 0.4V below the normal value of 1.2. If you specify 16, you'd get 0.4V ABOVE the normal value of 1.2V, or 1.6V. The fact that someone carefully specified "8" and "1.4V" as the upper limit in the examples leads me to think that it is likely to shorten the life of your raspberry pi significantly if you would specify values above "8". So: don't specify values above zero, but if you do, don't go above 8.</ref>

| Enables turbo mode from boot for the given value in seconds (up to 60) or until cpufreq sets a frequency. Can help with sdcard corruption if overclocked. Default 0 <ref name=initial_turbo>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&start=425#p180099</ref>

| Disables SMPS current limit protection when set to "0x5A000020". Can help if you are currently hitting a reboot failure when overclocking too high. <ref name=current_limit_override>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&start=325#p170793</ref>

|}

|}

+

+

===force_turbo mode===

+

force_turbo=0

+

enables dynamic clocks and voltage for the ARM core, GPU core and SDRAM.

+

When busy, ARM frequency go up to "arm_freq" and down to "arm_freq_min" on idle.

+

"core_freq", "sdram_freq" and "over_voltage" behave the same. "over_voltage" is limited to 6 (1.35V).

+

Non default values for the h264/v3d/isp parts are ignored.

+

force_turbo=1

+

disables dynamic clocking, so all frequencies and voltages stay high.

+

Overclocking of h264/v3d/isp GPU parts is allowed as well as setting "over_voltage" to 8 (1.4V).

ARM, SDRAM and GPU each have their own PLLs and can have unrelated frequencies<ref name=freq_relationship>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&start=125#p126308</ref>.

+

The GPU core, h264, v3d and isp share a PLL, therefore need to have related frequencies. ARM, SDRAM and GPU each have their own PLLs and can have unrelated frequencies.<ref name=freq_relationship>http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=6201&start=275#p168042</ref>

−

The GPU core, h264, v3d and isp share a PLL, so need to have related frequencies. PLL will be set to:

GPU core, h264, v3d and isp should all be integer divisors of pll_freq.

+

The following is not necessary with "avoid_pwm_pll=1".

−

So core_freq=480 sets pll_freq=960. That would allow a v3d_freq/h264_freq/v3d_freq of 320 with an integer divider of 3.

+

−

This is not necessary with "avoid_pwm_pll=1".

+

pll_freq = floor(2400 / (2 * core_freq)) * (2 * core_freq)

+

gpu_freq = pll_freq / [even number]

+

+

The effective gpu_freq is automatically rounded to nearest even integer, so asking for core_freq=500 and gpu_freq=300 will result in divisor of 2000/300 = 6.666 => 6 and so 333.33MHz.

==Tested values==

==Tested values==

−

The following table shows some successfull attempts of overclocking. These settings may not work on every device and can shorten the life of the Broadcom SoC. '''Warranty will be voided if overvoltage is used.'''

+

The following table shows some successfull attempts of overclocking, which can be used for orientation. These settings may not work on every device and can shorten the lifetime of the Broadcom SoC.

File format

The format is "property=value" where value is an integer. You may specify only one option per line. Comments may be added by starting a line with the '#' character.

Here is an example file

# Set stdv mode to PAL (as used in Europe)
sdtv_mode=2
# Force the monitor to HDMI mode so that sound will be sent over HDMI cable
hdmi_drive=2
# Set monitor mode to DMT
hdmi_group=2
# Set monitor resolution to 1024x768 XGA 60Hz (HDMI_DMT_XGA_60)
hdmi_mode=16
# Make display smaller to stop text spilling off the screen
overscan_left=20
overscan_right=12
overscan_top=10
overscan_bottom=10

gpu_mem_256 GPU memory in megabyte for the 256MB Raspberry Pi. Ignored by the 512MB RP. Overrides gpu_mem. Max 192. Default not set

gpu_mem_512 GPU memory in megabyte for the 512MB Raspberry Pi. Ignored by the 256MB RP. Overrides gpu_mem. Max 448. Default not set

CMA - Dynamic Memory Split

The firmware and kernel as of 19. November 2012 supports CMA, which means the memory split between ARM and GPU is managed dynamically at runtime.
You can find an example config.txt here.

cma_lwm When GPU has less than cma_lwm (low water mark) memory available it will request some from ARM.

cma_hwm When GPU has more than cma_hwm (high water mark) memory available it will release some to ARM.

The following options need to be in cmdline.txt for CMA to work:

coherent_pool=6M smsc95xx.turbo_mode=N

Video

Video mode options

sdtv_mode defines the TV standard for composite output (default=0)

sdtv_mode=0 Normal NTSC
sdtv_mode=1 Japanese version of NTSC – no pedestal
sdtv_mode=2 Normal PAL
sdtv_mode=3 Brazilian version of PAL – 525/60 rather than 625/50, different subcarrier

sdtv_aspect defines the aspect ratio for composite output (default=1)

sdtv_aspect=1 4:3
sdtv_aspect=2 14:9
sdtv_aspect=3 16:9

sdtv_disable_colourburst disables colour burst on composite output. The picture will be monochrome, but possibly sharper

sdtv_disable_colourburst=1 colour burst is disabled

hdmi_safe Use "safe mode" settings to try to boot with maximum hdmi compatibility. This is the same as the combination of: hdmi_force_hotplug=1, config_hdmi_boost=4, hdmi_group=1, hdmi_mode=1, disable_overscan=0

hdmi_safe=1

hdmi_ignore_edid Enables the ignoring of EDID/display data if your display is a crappy Chinese one

hdmi_ignore_edid=0xa5000080

hdmi_edid_file when set to 1, will read the edid data from the edid.dat file instead of from the monitor.[1]

hdmi_edid_file=1

hdmi_force_edid_audio Pretends all audio formats are supported by display, allowing passthrough of DTS/AC3 even when not reported as supported.

hdmi_force_edid_audio=1

avoid_edid_fuzzy_match Avoid fuzzy matching of modes described in edid. Picks the standard mode with matching resolution and closest framerate even if blanking is wrong.

framebuffer_depth console framebuffer depth in bits per pixel. Default is 16. 8bit is valid, but default RGB palette makes an unreadable screen. 24bit looks better but has corruption issues as of 20120615. 32bit has no corruption issues but needs framebuffer_ignore_alpha=1 and shows the wrong colors as of 20120615.

framebuffer_ignore_alpha set to 1 to disable alpha channel. Helps with 32bit.

test_mode enable test sound/image during boot for manufacturing test.

disable_overscan set to 1 to disable overscan.

config_hdmi_boost configure the signal strength of the HDMI interface. Default is 0. Try 4 if you have interference issues with hdmi. 7 is the maximum.

display_rotate rotates the display clockwise on the screen (default=0) or flips the display.

Boot

disable_commandline_tags stop start.elf from filling in ATAGS (memory from 0x100) before launching kernel

cmdline (string) command line parameters. Can be used instead of cmdline.txt file

kernel (string) alternative name to use when loading kernel. Default "kernel.img"

kernel_address address to load kernel.img file at

kernel_old (bool) if 1, load kernel at 0x0

ramfsfile (string) ramfs file to load

ramfsaddr address to load ramfs file at

initramfs (string address) ramfs file and adress to load it at (it's like ramfsfile+ramfsaddr in one option). NOTE: this option uses different syntax than all other options - you should not use "=" character here. Example:

boot_delay_ms wait for given number of milliseconds in start.elf before loading kernel. Default 0

avoid_safe_mode if set to 1, safe_mode boot won't be enabled. Default 0

Overclocking

WARNING: Setting any of the parameters which overvolt your Raspberry Pi can set a permanent bit within the SOC and your warranty is void. Warranty will be voided when you use force_turbo or current_limit_override or temp_limit>85 together with over_voltage>0.[2] So If you care about the warranty, do not adjust voltage.

The latest kernel has a cpufreq kernel driver with the "ondemand" governor enabled by default. It has no effect if you have no overclock settings.
But when you do, the arm frequency will vary with processor load. Non default values are only used when needed according to the used governor. You can adjust the minimum values with the *_min config options or disable dynamic clocking with force_turbo=1. [3]

Overclock and overvoltage will be disabled at runtime when the SoC reaches 85°C to cool it down . You should not hit the limit, even with maximum settings at 25°C ambient temperature. [4]

Also at your own risk you can try overscan settings from our wiki. These were posted on the forum and are not confimed to work.

Overclocking options

Option

Description

arm_freq

Frequency of ARM in MHz. Default 700

gpu_freq

Sets core_freq, h264_freq, isp_freq, v3d_freq together. Default 250

core_freq

Frequency of GPU processor core in MHz. It have an impact on ARM performance since it drives L2 cache. Default 250

h264_freq

Frequency of hardware video block in MHz. Default 250

isp_freq

Frequency of image sensor pipeline block in MHz. Default 250

v3d_freq

Frequency of 3D block in MHz. Default 250

avoid_pwm_pll

Unlink core_freq from the rest of the gpu. Can cause low quality analog audio, which should be fixed with latest firmware. Default 0

Disables SMPS current limit protection when set to "0x5A000020". Can help if you are currently hitting a reboot failure when overclocking too high. [7]

force_turbo mode

force_turbo=0

enables dynamic clocks and voltage for the ARM core, GPU core and SDRAM.
When busy, ARM frequency go up to "arm_freq" and down to "arm_freq_min" on idle.
"core_freq", "sdram_freq" and "over_voltage" behave the same. "over_voltage" is limited to 6 (1.35V).
Non default values for the h264/v3d/isp parts are ignored.

force_turbo=1

disables dynamic clocking, so all frequencies and voltages stay high.
Overclocking of h264/v3d/isp GPU parts is allowed as well as setting "over_voltage" to 8 (1.4V).
[8]

Clocks relationship

The GPU core, h264, v3d and isp share a PLL, therefore need to have related frequencies. ARM, SDRAM and GPU each have their own PLLs and can have unrelated frequencies.[9]

↑ 5.05.15.25.3What this means is that you can specify -16 and expect about 0.8V as the GPU/core voltage. This is 0.4V below the normal value of 1.2. If you specify 16, you'd get 0.4V ABOVE the normal value of 1.2V, or 1.6V. The fact that someone carefully specified "8" and "1.4V" as the upper limit in the examples leads me to think that it is likely to shorten the life of your raspberry pi significantly if you would specify values above "8". So: don't specify values above zero, but if you do, don't go above 8.